Hi all,
I just had this crash in mpl:
/usr/lib/python2.3/site-packages/matplotlib/texmanager.py in
get_dvipng_version(self)
299 def get_dvipng_version(self):
300 if self.dvipngVersion is not None: return
self.dvipngVersion
--> 301 sin, sout = os.popen2('dvipng --version')
302 for line in sout.readlines():
303 if line.startswith('dvipng '):
/usr/lib/python2.3/os.py in popen2(cmd, mode, bufsize)
614 def popen2(cmd, mode="t", bufsize=-1):
615 import popen2
--> 616 stdout, stdin = popen2.popen2(cmd, bufsize)
617 return stdin, stdout
618 __all__.append("popen2")
/usr/lib/python2.3/popen2.py in popen2(cmd, bufsize, mode)
145 specified, it sets the buffer size for the I/O pipes.
The file objects
146 (child_stdout, child_stdin) are returned."""
--> 147 inst = Popen3(cmd, False, bufsize)
148 return inst.fromchild, inst.tochild
149
/usr/lib/python2.3/popen2.py in __init__(self, cmd, capturestderr, bufsize)
40 if capturestderr:
41 errout, errin = os.pipe()
---> 42 self.pid = os.fork()
43 if self.pid == 0:
44 # Child
OSError: [Errno 12] Cannot allocate memory
This was in a long-running session with very large memory allocations,
but it dawned on me that get_dvipng_version(self) should cache its
return value. There's no point in forcing a popen() call every single
time, is there?
I don't know the texmanager code, so I don't want to touch it myself.
But if the idea is OK, a simple property tag is enough to cache:
In [3]: def cached():
...: try:
...: return cached.cachedvalue
...: except AttributeError:
...: cached.cachedvalue=42
...: return cached.cachedvalue
...:
In [4]: cached()
Out[4]: 42
I also just saw pylab crash when a user was trying to run with $PWD
being something he didn't have write access to. Are there any checks in
the code to fall back to /tmp or something sensible if texmanager can't
write the temp files it needs? Sorry for not giving a traceback, but I
only saw this on someone else's screen while helping them, and for some
odd reason it's not happening on my box.
Cheers,
f